As examples of such a droplet discharge device, devices that manufacture color filters for color liquid crystal panels, and inkjet printers (hereinafter, “printer”), etc., are known in the art. An inkjet printer performs printing on a medium, which is supported by a platen, by discharging an ink while causing a printer head, which is arranged facing the platen, to move horizontally. For example, a printer is disclosed in Patent Document 1 that performs printing on a medium, which is placed on a platen, by discharging an ink from a printer head that is caused to move along a guide rail.
As an example, printers are known that perform printing with ultraviolet curable ink (hereinafter, referred to as UV ink) that is cured when irradiated with an ultraviolet light. Because the UV ink has excellent weather resistance and water resistance properties, there is an advantage that a printed material can be used for an outdoor advertisement flyer, etc., so that the printed material printed with the UV ink can be used for various purposes as compared with the printed matter printed with a water-soluble ink. The water-soluble ink penetrates the medium, and is cured inside the medium, whereas, the UV ink does not penetrate the medium, and is cured on the surface of the medium. Therefore, there is an advantage that printing can be performed on a medium made of a material, such as, vinyl chloride material, that does not easily allow penetration of the ink. Consequently, printing performed using the UV ink is widespread in the industrial field.
Recently, there is a demand for performing printing not only on sheet-like mediums but also on surfaces of various mediums having a three-dimensional shape. When performing printing on such three-dimensional mediums, merely placing the medium on the platen is not adequate to give it positional stability so that the printer cannot accurately recognize the position of the medium on the platen. Therefore, in the conventional technology, a jig that holds the medium is mounted is prepared and an operator accurately aligns a position of the jig relative to, for example, a reference position of a bed in a flatbed printer. Thus, when the medium is placed on the jig, the medium can be stably held and the position of the medium relative to the bed can be accurately recognized.